93
ISSN 1068-3755, Surface Engineering and Applied Electrochemistry, 2020, Vol. 56, No. 1, pp. 93–99. © Allerton Press, Inc., 2020.
Russian Text © The Author(s), 2018, published in Elektronnaya Obrabotka Materialov, 2018, No. 4, pp. 52–58.
Template Synthesis of Mesoporous Carbon Materials
for Electrochemical Capacitors
V. I. Mandzyuk
a,
*, I. F. Myronyuk
a
, V. M. Sachko
a
, and I. M. Mykytyn
a
a
Vasyl Stefanyk Precarpathian National University, Ivano-Frankivsk, 76018 Ukraine
*e-mail: mandzyuk_vova@ukr.net
Received March 2, 2018; revised April 2, 2018; accepted April 26, 2018
Abstract—The effect of AlOOH endo-template on porous structure, electrical conductivity, and electro-
chemical properties of lactose-derived carbon materials is investigated in the article. It is found that a carbon
material with a specific surface of 1707 m
2
/g and a total pore volume of 1.546 cm
3
/g can be obtained when
the mass ratio of C : AlOOH is 1 : 1. Electrochemical capacitors, formed on the base of the synthesized sam-
ples, have specific capacity of a wide range (66–170 F/g), at discharge current 10 mA. The developed meso-
porous structure of carbon materials synthesized via the template method allows charge/discharge electro-
chemical capacitors at currents up to 200 mA, providing the value of specific capacity 121 F/g.
Keywords: mesoporous carbon, template synthesis, porous structure, specific conductivity, electrochemical capacitor
DOI: 10.3103/S1068375520010123
INTRODUCTION
Carbon materials (CMs), obtained as a result of
thermal degradation of polymers or natural raw mate-
rials (wood, shells of fruit stones, food waste), are
widely used in modern science and technology. They
act as sorbents, carriers of catalysts, membranes for
separating gas mixtures, electrodes of galvanic power
sources, and electrochemical capacitors (ECs), etc.
[1–8]. CMs used for these purposes should have a cor-
responding pore size distribution (PSD). To obtain
the desirable distribution, methods of thermal or ther-
mochemical modification of raw material or carbona-
ceous material are used [6, 9–13]. In most cases, car-
bonaceous precursors are mixed with pore-forming
agents [8, 14–17] or templates [18–23] to obtain CMs
with predetermined pore structure.
As a rule, CMs have microporous structure, when
using the methods of thermal or thermochemical
modification. Activation thermochemical processes,
which lead to an increase in the pore volume in a car-
bon matrix, are due to the reactive interaction of H
2
O
or CO
2
molecules with carbon atoms at temperatures
of 800–1100°C [24, 25].
Carbon structures with the required ratio of micro-
and mesoporous are synthesized using reagents KOH,
K
2
CO
3
or ZnCl
2
[26–30]. When heated composite
mixtures consisting of a carbon precursor and indi-
cated compounds, K
2
O and ZnO particles are formed,
which form mesopores of 2–6 nm in size after remov-
ing from the carbon matrix. H
2
O, CO
2
, and HCl mol-
ecules, released due to thermodissociation of reagents,
are involved in the oxidation of carbon atoms and con-
tribute to the growth of pore volume in the material.
To obtain spatially ordered porous CMs the meth-
ods of exo- and endotemplating are used. The first
method involves thermolytic decomposition of a car-
bonaceous precursor in the volume of pores of inor-
ganic matrices—zeolites [31–33], silica molecular
sieves or alumina membranes [34–37]. The voids of
exo-templates as a result of organic matter carboniza-
tion are carbon skeletons, and free volume as pores
and channels is formed after dissolution and removal
of the matrix. The endo-template method consists in
filling the carbon precursor volume by nanoparticles
of an inorganic oxide material (for example, SiO
2
or
Al
2
O
3
) and washing of these particles from CMs by an
aqueous solution of KOH, fluoride or chloride acid
after carbonation of the precursor [38–40].
The mesoporous aluminum hydroxide AlOOH,
formed during thermal decomposition of aluminum
nitrate nonahydrate Al(NO
3
)
3
∙ 9H
2
O [41], is one of
the endo-templates that can be used to correct the
porous structure of CMs. Therefore, the purpose of
this work is to obtain CMs using AlOOH endo-tem-
plate and to find out its effect on the porous structure,
electrical conductivity of CMs, and electrochemical
properties of ECs with electrodes based on them.
EXPERIMENTAL
Carbon was obtained from the crystalline D-lac-
tose (C
12
H
22
O
11
), as a precursor, at 400°C for 30 min
in an air atmosphere. Subsequent activation of carbon